The initiative has an endearing backstory. It was developed six years ago by St. Ninians Primary School in Stirling in central Scotland after children and teachers felt the pupils needed to be fitter.
Other schools quickly realized the value, and it started to spread. It is now happening in around half of Scottish primaries and a quarter of those in England, along with schools in the United States, the United Arab Emirates, Nepal and Australia.
With all this enthusiasm, it was time for researchers to ask the obvious question: Is it really worth doing? We have been part of a collaboration between the Universities of Stirling and Edinburgh that has published the first results.